Wearable coin-cell peripheral nerve-field stimulator reverse-engineering schematic with boost stimulation rail, micro-USB, electrode outputs, and bottom return ring contact.

Ultra-Low Power 10-LED Coin-Cell Roulette Chaser with Sound

Simple CR2032-powered binary wristwatch with a low-power MCU, readable LED bit display, pushbutton wake/time setting, and PCB shape suitable for a 3D-printed case.